WASHINGTON -- U.S. intelligence officials are frustrated that the Russian government is withholding information about threats to Olympic venues coming from inside Russia, several lawmakers said during talk shows Sunday.

"It means that we're less effective in protecting our people, and that's a frustration," Schiff said.

More than 70,000 Russian security officers have been deployed to protect the Olympic venues in Sochi. Russian President Vladimir Putin describes the layers of security around Sochi as the "ring of steel."

The American ambassador to Russia, Michael McFaul, said the U.S. is "quite satisfied" with the cooperation coming from Russian security officials.

"We always want to know more and if you work in the intelligence business you always want more information from any interlocutor, from any partner country," McFaul said.

"That said, we do not have an interest in embarrassing the Russians. We have exactly the same interests with them when it comes to the security of everyone here in Sochi," he said, speaking on NBC's "Meet the Press" from the Olympics.

Last week, the U.S. Transportation Security Administration banned passengers flying from the U.S. to Russia from bringing liquids in their carry-ons. The alert was based on intelligence that terrorists might try to smuggle explosives onto airplanes inside toothpaste tubes.

Some of that information came from Russian officials, Rep. Pete King (R-N.Y.) said Sunday on CBS's "Face the Nation."

But King, who sits on both the House Intelligence and Homeland Security committees, said the Russians aren't cooperating to the same extent as the Chinese, British and Greeks did during previous Olympic games.

"They are still reluctant to give intelligence that they feel would allow us to determine their sources and methods, and also there's still a certain amount of pride, I believe, that they feel they can handle a lot of this on their own," King said.

Rep. Michael McCaul (R-Texas), chairman of the House Homeland Security Committee, said on "Fox News Sunday" that the Russians, so far, have been cooperative when it comes to sharing information about potential terrorist operations planned outside of Russia.

"When it comes to internal operations, I think less so. That's where we'd like to work more closely with them," McCaul said.

Along with the possibility of bombs being planted on aircraft flying into Sochi International Airport, another major threat comes from suicide bombers potentially exploding themselves at train and bus terminals around the region, McCaul said.

McCaul toured the security installations in Sochi last month and said the Olympic Village in Sochi appeared to be well fortified. But McCaul said he thinks there is a "high degree of probability" that a bomb will detonate in the surrounding region, where Russia has been fighting an Islamist separatist movement in Chechnya, Dagestan and elsewhere.

"I hope I'm wrong in this assessment, but you're talking about an area of the world where suicide bombers go off all the time," McCaul said.